In general, power battery modules that are mounted, for example, to electric cars or hybrid cars are configured by connecting a large number of electric cells in series via bus bars. Known examples of the battery modules of this kind are provided with detection terminals for detecting the states of the electric cells constituting an electric cell group.
As an example of such a battery module, a battery module is known that is formed by attaching a wiring module including bus bars and detection terminals to an electric cell group including a plurality of electric cells that are lined up in a row, and assembling these components. For example, in the wiring module described in JP 2011-8955A, a plurality of bus bars and detection terminals are held at predetermined positions of an insulating bus bar holding member, and detection wires that are drawn from the detection terminals are collectively accommodated in a wire accommodating groove provided in the bus bar holding member.